Use conventional 52 mm screw-thread filters with selected Canon super-telephoto lenses. Simply insert the filter into the adapter and drop the assembly into the lens drop-in filter slot. The colour of the Canon 52 (WIII) filter holder will differ from the colour of the body of super telephoto lenses other than the EF 400mm f/2.8L IS III USM and EF 600mm f/4L IS III USM. This will not affect performance and the filter holder is fully compatible otherwise. Benefits Use your existing collection of 52mm filters with super-telephoto lenses Create special effects and reduce brightness with ND filters Compact and portable, so it can always be in your bag Maintains the weather sealed protection against dust and moisture What\'s in the box Canon 52 (WIII) Drop-in Screw Filter Holder Compatibility EF 300mm f/2.8L IS USM EF 300mm f/2.8L IS II USM EF 400mm f/4 DO IS USM EF 400mm f/4 DO IS II USM EF 200mm f/2L IS USM EF 400mm f/2.8L IS USM EF 400mm f/2.8L IS II USM EF 400mm f/2.8L IS III USM EF 500mm f/4L IS USM EF 500mm f/4L IS II USM EF 600mm f/4L IS USM EF 600mm f/4L IS II USM EF 600mm f/4L IS III USM EF 800mm f/5.6L IS USM EF 200-400mm f/4L IS USM built in extender 1.4x RF 400mm F2.8L IS USM RF 600mm F4L IS USM RF 800mm F5.6L IS USM RF 1200mm F8L IS USM